322 MOLLUSCA, 
Much like C. alternatus, Sowb., which, however, has radiating ribs 
upon its lateral areas and terminal valves. 
Figure 433, dorsal view of the shell, enlarged; 433, details of 
sculpture, magnified ; 433 6, natural size. 
CHITON INTERSTINCTUS (Gould). 
Testa parva, rotundato-ovalis, viz carinata, rubricata, ubique quincun- 
cialiter punctata; valvis ad apicem acutis, lined elevata luteo-macu- 
lata divisis, areis lateralibus et valvis terminalibus juata marginem 
plicatis: margo coriaceus granuloso-squamosus. 
SHELL minute, oval, rather broad, of a flesh-red colour, everywhere 
minutely punctured in quincunx. Valves narrow, slightly pointed at 
their apex, the lateral and central areas separated by a raised line, 
having two faint yellowish spots on each side and another at the apex, 
only seen on careful examination. On the lateral areas near the mar- 
gin are three or four obtuse folds, reaching about halfway to the apex: 
these are continued round on the two terminal valves; posterior valve 
semicircular, with a slight umbo near the preceding valve. Margin 
red, covered with minute, granular scales; marginal fissures of the 
anterior valve ten or eleven, with corresponding rays on the interior. 
Interior bluish-white, rusty at the centre. 
Length half an inch; breadth three-tenths of an inch. 
Found at Puget Sound, Oregon. 
A very small species, about the size and colour of C. castaneus, but 
may be recognised by the plaited border and the yellow spots on the 
line dividing the areas; some specimens, however, are more bronzed, 
and without the yellow flecks. It has the size and many characters 
of C. Sitchensis, Middendorff. 
Figure 423, dorsal view of the shell; 423 a, details of sculpture ; 
423 b, three valves, enlarged. 
